Evaluation of DICOM Viewer Software for Workflow Integration in Clinical Trials Daniel Haak1*, Charles-E. Page, Klaus Kabino, Thomas M. Deserno Department of Medical Informatics, Uniklinik RWTH Aachen, 52057 Aachen, Germany ABSTRACT The digital imaging and communications in medicine (DICOM) protocol is nowadays the leading standard for capture, exchange and storage of image data in medical applications. A broad range of commercial, free, and open source software tools supporting a variety of DICOM functionality exists. However, different from patient’s care in hospital, DICOM has not yet arrived in electronic data capture systems (EDCS) for clinical trials. Due to missing integration, even just the visualization of patient’s image data in electronic case report forms (eCRFs) is impossible. Four increasing levels for integration of DICOM components into EDCS are conceivable, raising functionality but also demands on interfaces with each level. Hence, in this paper, a comprehensive evaluation of 27 DICOM viewer software projects is performed, investigating viewing functionality as well as interfaces for integration. Concerning general, integration, and viewing requirements the survey involves the criteria (i) license, (ii) support, (iii) platform, (iv) interfaces, (v) two- dimensional (2D) and (vi) three-dimensional (3D) image viewing functionality. Optimal viewers are suggested for applications in clinical trials for 3D imaging, hospital communication, and workflow. Focusing on open source solutions, the viewers ImageJ and MicroView are superior for 3D visualization, whereas GingkoCADx is advantageous for hospital integration. Concerning workflow optimization in multi-centered clinical trials, we suggest the open source viewer Weasis. Covering most use cases, an EDCS and PACS interconnection with Weasis is suggested. Keywords: DICOM, EDCS, eCRF, Data Capture, Integration, Interfaces, Display 1. INTRODUCTION Nowadays, the digital imaging and communications in medicine (DICOM) protocol of the National Electrical Manufacturers Association (NEMA) and the American College of Radiology (ACR) has been established as the leading standard for image data management in medical applications [1]. Since its release in 1993, DICOM is applied to capture, exchange and store image data via DICOM workstations and picture archiving and communication systems (PACS). Due to DICOM’s popularity, a broad range of commercial as well as free or open source software tools have been developed up to today. Almost 350 free software projects are currently listed in the database of the I Do Imaging web site (http://www.idoimaging.com/). Furthermore, medical imaging is looming large today in clinical trials. Image-based surrogate endpoints offer qualitative and quantitative disease findings improving eligibility, efficacy, and security evaluation in studies [2]. Here, patient’s data is captured using electronic data capture systems (EDCS), which provide electronic case report forms (eCRFs) instead of the traditional paper-based CRFs. ECRFs allow data evaluation by automatic range checks and can be accessed via web. This improves data quality and simplifies access in multi-centered trials [3,4]. However, EDCS lack in support of DICOM. Neither a structured way to integrate DICOM data into EDCS, nor interfaces for communication with PACS exist. Up to now, visualization of DICOM objects in eCRFs is impossible. Appropriate DICOM viewers are not yet integrated. Four increasing levels of integration for connecting a DICOM viewer, a PACS and an EDCS have been discussed in previous work [5]. According to improve functionality and optimize the workflow, the requirements to interfaces of the software components increase with each of the levels. Components of an integrative system are not only required to offer rich functionality for fulfilling their designated purpose (e.g. visualization features for a viewer), but also have to include a wide range of interfaces. 1Corresponding author: Daniel Haak, Department of Medical Informatics, RWTH Aachen University, Pauwelsstr. 30, D - 52057 Aachen, Germany, email: [email protected]; phone: +49 241 80 85174, fax: +49 241 80 82426. Medical Imaging 2015: PACS and Imaging Informatics: Next Generation and Innovations, edited by Tessa S. Cook, Jianguo Zhang, Proc. of SPIE Vol. 9418, 94180O © 2015 SPIE · CCC code: 1605-7422/15/$18 · doi: 10.1117/12.2082051 Proc. of SPIE Vol. 9418 94180O-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/10/2015 Terms of Use: http://spiedl.org/terms Finding optimal software in the large pool of DICOM tools is challenging. Focusing on open source DICOM tools, Nagy published a list of suitable software including server, viewer, image processing, teaching file tools, web-based PACS, and general toolkits, which include conversion and code libraries [6]. In 2003, Horii has presented a survey of free and commercial DICOM viewers [7]. In his work, he investigated image viewing functionality such as supported DICOM information object types, included image processing methods and ability to export images in other formats. As result, he stated that tools, which are easy to use and include rich functionality, can also be found in the open source field. However, Nagy and Horii’s publications rather focused on presenting a collection of tools, than a comprehensive and systematic comparison. In 2007, Liao et al. have published an evaluation of 21 free non-diagnostic DICOM viewers [8]. The survey has been focused on free and standalone DICOM viewers, which provide a graphical user interface (GUI). In the evaluation, the viewers have been investigated based on a set of 28 various DICOM data sets. During this, all viewers have been analyzed regarding the criteria (i) data import and (ii) export; (iii) header viewing; (iv) two-dimensional (2D) and (v) three-dimensional (3D) image viewing, (vi) support, (vii) portability, (viii) workability, and (ix) usability. All criteria have been defined as “yes”/”no” categories except workability and usability, which have been assessed rather qualitatively (e.g. by subjective percent values). Optimal DICOM viewers have been suggested for the application profiles inexperience users, data conversion, and volume rendering. However, all these publications are out of date and completely disregard any interfacing functionality. In this paper, a comprehensive evaluation of open source, free and commercial DICOM viewer software is performed. Beside concerning general and viewing functionality of the tools, the focus lays on aspects of integration into system environments. We focus in particular on controlled clinical trials with respect to extensive 3D imaging, interconnection to hospital’s data, and optimal workflow. 2. MATERIAL AND METHODS 2.1 Catalog of Criteria A catalog of 29 criteria in 6 groups defining requirements for general (G), integration (I) and viewing (V) functionality has been built up, concerning (i) license and (ii) support; (iii) platform and (iv) interfaces; as well as (v) 2D and (vi) 3D image viewing, respectively. Interface criteria are based on functionality which has been found during the survey and valued as advantageous. The viewing criteria have been mainly adopted by the work of Liao et al. Facing on integration of systems, criteria such as data import and export have been discharged. To avoid subjectivity, all criteria are designed as simple “yes” (+) or “no” (-) categories. 2.1.1 License The first group of criteria focusses on the licensing policies of the software and maps the viewers to open source, free or commercial products. G1 – Open Source: Open source software is free to use and its source code is public available. In addition, users are typically allowed to modify the software and adopt its functionality to their needs. However, a wide range of open sources licenses with specific characteristics exists (e.g. GNU General Public License (GPL), Berkeley Software Distribution (BSD) license). G2 – Free: Free software is costless, too, but its source code is not public available and cannot be modified. G3 – Commercial: A commercial software product is marketed by a company and the software underlies a fee-based licensing model. 2.1.2 Support Support requirements identify in which way helpful information for the software is provided. G4 – Documentation: Written documentation for the software including manuals is available. G5 – Mail: A mailing list is offered to get support via mail communication. G6 – Forum: A web-based forum is provided in case support is needed. Proc. of SPIE Vol. 9418 94180O-2 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/10/2015 Terms of Use: http://spiedl.org/terms G7 – Wiki: A wiki web page is available for users. 2.1.3 Platform The platform criteria concerns the viewer’s system environment and is structured in standalone, web, platform- independent, and mobile device applications. I1 – Standalone: Standalone applications are designed to be only runnable on a specific operating systems (e.g. Windows, Linux or Mac OS). Usually specific software versions for various platforms exists. I2 – Web: Web applications are running on a web server usually based on a Linux or Windows operating system and can be accessed by client systems via modern browsers. I3 – Platform Independent: A few programming languages (e.g. Java) are platform-independent and can be executed on standalone systems (e.g. using Java runtime environment (JRE)) or transferred by the web server to a client system (e.g. using Java